Approximately 80% of people over 30 complain of some degree of memory loss. Normal memory loss includes the misplacing an item or forgetting the name of a person that you just met. Memory loss associated with mild cognitive impairment (MCI), a condition characterized by a memory deficit, but not dementia, is more severe than normal memory loss and often involves continuing problems in delayed recall of information. Most individuals who eventually develop dementia go through a phase of mild cognitive impairment, and some individuals with MCI develop the clinical stages of Alzheimer's Disease (AD).
Dementia, a structurally-caused, permanent or progressive decline of intellectual function, is one of the most serious disorders facing the elderly population. Dementia, which normally results in a loss of short-term and/or long-term memory, interferes substantially with social as well as economic activities. Memory loss is not only characteristic of the normal aging process but also of many neurological disorders. The risk of dementia is correlated with age and doubles every five years after the age of 60. Studies report that up to 50% of people over the age of 85 are afflicted with this disorder. An estimated 60-80% of elderly nursing home residents are affected by this disease.
Notably, the various forms of dementia are attributable to different causes. Many neurological disorders, such as Alzheimer's disease, can lead to forms of dementia. For example, Alzheimer-type dementia has been attributed to specific cellular and histological degenerative processes resulting in brain atrophy and the loss of cells from the basal forebrain, cerebral cortex, and other brain areas. Stroke, head trauma, and epilepsy can also lead to memory impairment. Epilepsy, a brain disorder in which neurons signal abnormally, can cause strange sensations, emotions, and behavior, or sometimes convulsions, muscle spasms, and loss of consciousness.
MCI patients over the age of 65 develop Alzheimer's Disease, one of the most common forms of dementia, at a rate of 12-15% yearly, which greatly exceeds the 1% to 2% incidence in normal controls healthy people. Thus, early treatment of patients with MCI could prevent further cognitive decline, including development of Alzheimer's disease. Alzheimer's disease is a degenerative brain disorder that afflicts millions of people worldwide. Alzheimer's Disease can affect memory, mood, personality, and cognitive ability. As the average human life-span continues to increase, the number of people developing Alzheimer's Disease at some point in their lives is escalating rapidly. Currently, an estimated one in twenty people over the age of 65 are affected by some form of dementia. In persons over the age of 80, that number rises to one in five.
Existing medications for neurological disorders and memory weaknesses are not always well tolerated, nor have they been proven effective in alleviating symptoms of dementia and memory loss. In addition, drugs, such as anti-epileptic drugs, can interfere with the effectiveness of other medications, such as oral contraceptives. Furthermore, while gingko biloba, piracetam, and various other “smart drugs” are being actively marketed, no proven memory-enhancing drug exists.
With the increasing lifespan of people, the lack of drugs that treat the biochemical causes of neurological disorders and memory impairment is becoming an acute problem. Thus, there exists a need in the art for drugs that can alleviate MCI, dementia and improve cognition and memory.